Ok, I'll ask  what is the benefit from having an external regulator
     as opposed to an
     internal?  T.W.



The issue is not so much that external is better than internal, but
rather what failure modes are there & how can they be addressed.  By and
large, internally regulated alternators do not provide external access
to the alternator field current.  The SL alternator which comes stock
for the RX-7 falls into this category.  The reason you might care about
this is in the event of a regulator failure.  Should the regulator fail,
uncontrolled voltage will flow to the aircraft.  In the case of the
RX-7's SL alternator there is no way -- by design -- to shut the
alternator down without stopping all engine rotation.  The alternator is
designed to use +12V on the "S" line to initiate the field current, but
once established, removing the +12V will not shut the alternator down --
only stopping the engine will reset the alternator to "off".

So - in this case there is a compelling reason to "fix" the design, and
using an external regulator is the only way.

Mark Supinski


Mark sent a 4.7 meg pdf but I converted it to 9 jpgs which are smaller overall.
Here are the first five. I suggest you print them and take them to the shop.

-------------------------------------------------------------

Next four.
-- 
Paul Lamar ...No rotor no motor.

A much easier and better way to protect the electrical system is to install
an over voltage protector, sometimes known as a voltage dependant resistor.
This device is normally open circuit but at the specified voltage, 15 in our
case, they short circuit. Short circuit current is only limited by the
wiring resistence. If the alternater goes high voltage its fuse, or fusable
link, blows and you fly home on the battery.
Its a good idea to protect all the electronics with one each, they are very
cheap, the engine can then be started without the ancient practice of
turning all the radios etc. off.

Happy new year from Ian Beadle. (Bolting engine on tomorrow)


The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2005 All world wide rights reserved.